Gas treatment



Oct. 9, 1934 E, p so I 1,976,629

GAS TREATMENT Filed NOV. 10, 1952 INVENTOR EDWARD PARKINSON Patented Oct. 9, 1934 vireo STATES PATENT 3 Claims.

The invention relates to a process and apparatus for washing, separating and collecting the smoke and fumes coming from a smoke stack and more particularly'to a process and apparatus applicable to such smoke and fumes as are found in the smoke stacks of smelting plants.

One object of the invention is. to prevent the release of objectionable smoke and fumes into the atmosphere from the smoke stackof' any furnace, and another object is to perform this in such a manner as to separate and collect the various solid and gaseous ingredients. A further object of the invention is to perfect this separation of the various constituents in such manner that none of the objectionable constituents are released into the open air. Still another object of the invention is to obtain this elimination and separation by the use of energy which otherwise would be lost.

In known devices for the elimination of smoke and fumes in the smoke stack of an industrial plant it has been suggested that sprays of water should be used to catch the particles of carbon or certain other solid constituents in the stack and cause their deposit. However, no effective means have heretofore been known for eliminating not only all the solid but also the objectionable gaseous constituents which normally pass out through the smoke stack. According to the present invention the upper end of the smoke stack is closed and nothing escapes into the open air, the constituents being reduced in volume, collected and separated in the manner which will now be described.

Referring now to the preferred embodiment of my invention illustrated in partial sectional elevation in the drawing, there is a vertical smoke stack A with a furnace flue B and an oven flue C leading into it near the bottom. In the smoke stack are the smoke and fumes D rising upwardly therein. It will be observed that the top of the smoke stack is closed having no outlet to the air but that at one or more elevations there are pipes I let into the stack leading to a vertical drain pipe or condensing stack J. The upper end of this condensing stack is closed but mounted therein are means subjecting the smoke to a liquid spray namely, a sprinkling nozzle H adapted to spray water over whatever may be in the condensing stack.

The bottom of the condensing stack leads into a closed settling tank M. Near the top of this setting tank M is an outlet pipe N leading into a tank 0, and this tank is in turn connected near its upper end to a tank P. The tank P connects with another tank Q. From this last tank project a series of gasvalves 1, 2, 3, i, 5, Band at the top of this tank Q is another outlet pipe N. At the bottom of each of the tanks M, O; P and Q is a drain valveR.

In order to compensate for closing the top of the smoke stack means to make a draft such for instance as fans L are provided. In' the drawing a fan L. is shown in each connecting pipe 1, four fans in the condenser stack J, and one fan each in the tanks M, O, P and Q; These fans cause suflicient suction to keep thesmoke' moving out of the stack with the necessary speed.

I have discovered however, that the draft can be very much increased and elimination of the objectionable constituents of the smoke and fumes much aided if certain exploded mixtures are introduced into the smoke stack. I obtain these by the use of flames coming from the vent of explosion units, such as internal combustion engines. Thus, in the drawing the exhaust pipes F of explosion units (not shown) discharge their exploded mixtures U into the smoke stack. Two

of these exhaustpip'es from explosion units are shown discharging straight into the stack and the other two are shown discharging into the stack'through water-filledmuifiers G. The purpose of these water-filled mufflers G is to cause a mixture of exploded gases with water in such manner that live steam is also sprayed' on the smoke in the stack. I so locate these exhaust pipes that the exploded mixture U coming out of the exhaust pipes tends to force the smoke and V fumes D into connecting pipes I and thence into the condenser stack J. I thus produce an induced draft inthe' stack. The action of the explosion flame entering the stack also causes combusr' tion of unburned carbon, sulphur, etc., in the stack.

The majority of the solid constituents of the smoke and fumes D will come to rest in the settling tank M and are prevented from passing out of this tank to the tank 0 by a sieve orstrainer. The fan L in this tank M normally dipping its blades in; the water, since they'project beneath the level of the overflow pipe, causes agitation of the gases and the water coming from the condenser stack J and therefore any particles which are not precipitated in the condenser stack J will be precipitated in the tank M. There is an outlet pipe S in the tank M adapted to keep the level of the water in the tank M approximately constant in spite of the water coming down the condenser stack J.

In case at any time the exploded mixtures cause an unusual pressure in the stack safety valve means T, T T are provided at the top of the stack.

Having now described the construction of the apparatus shown in the drawing its operation will now be set forth.

Smoke and fumesD enter the stack A through the elements B and C, a draft is provided in the stack A by means of the fans L and explosion flames injected into the stack from the exhaust pipes F. If desired live steam can also be sprayed into the stack. The smoke and fumes are thus caused to leave the stack A through the con-' necting pipes I leading into the condensing stack J. Fans L cause a downward draft in the condensing stack, and at the same time the downward motion is assisted by a water spray projected from the sprinkling nozzle H at the top of the condensing stack. The spray also causes precipitation of the solid particles carried in suspension by the smoke and fumes D and likewise chills the mixture so that its volume. is further decreased while descending in the condensing stack. 7 v

The smoke and fumes D together with the water spray are carried into the settling tank M, the

solid particles settling to the bottom of the liquid which is entrapped in the bottom of this tank. The gaseous constituents and suspended pars ticles which havenot been condensed or absorbed in the water pass through the pipe and valve N into the'tank 0 where a further precipitation and settling takes place. The action in the tank O is also a settling action and the gas and volatile matter leave the tank near its top through another pipe and valve N passing into the next 1tank P, where a further settling takes place. The

gases in the tank P being further purified through settling leave this tank throughthe pipe and valve N entering the next tank Q of the series, where a final settling takes place. Gases contained in the tank Q maybe selectively removed at different elevations or levels (and'therefore at different densities) through the pipes and valves 1, 2, 3, 4, 5 and 6. These gases may also be removed for further treatment through the pipe and valve N at the top of the tank. It will be noted that the heavier products settling to the bottom.

ofeachtank may be removed as desired through outlet pipes and valves R;

A draft is maintained throughout by fansv located in each of the tanks which have been described. V

The number and size of the. fans, connecting pipes and tank may be varied without departing from the scope of the invention. Where in the claims the word smoke, is .used it shouldlbe understood to-include-the fumes. as well.

By means of the apparatus which has been 1 described, operating as above set forth,it is possiof objectionable fumes may be allowed to escape into the atmosphere or stored in tanks'as desired.

It will be further noted that products of economic Y value may be recovered from the bottom of the various settling tanks through the pipes and valves R. It is of course understood that the volume of the smoke and fumes received into the stack is greatly reduced by the action vof the liquid spray in the condensing stack and by the precipitation, settling and removal of solids carried by the smoke in the settling tank M, and the successive tanks into which the smoke passes after leaving the tank into a closed container to any great extent, and that therefore one or more outlets from the last tank in the series must be almost continually open.

Through theme of the present invention it has been made possible absolutely to control the smoke and fume-s ordinarily emitted from a smoke stack without sacrificingthe draft required for operating the furnace or roaster. The invention also provides very desirable means for obtaining Icy-products from smoke and gases in a smoke stack and for this purpose utilizes a combination of explosive products which have heretofore been wasted. a water spray and the gravity settling principle.

Iclaim:--

1. A method of preventing the'smoke in a stackfrom reaching the atmosphere, comprising the stepsof creating an induced draftin the stack; injecting streams of flaming gas under high pressure and live steam into the, smoke in the direc tion of flow .of the latter, leading the smoke from the stack, precipitating the solid constituents and collecting the same in a 'closed container and then passing the gases into another container.

2. A method of preventing the smoke in a stack from reaching the atmosphere, comprisingthe steps of creating an induced draft in the stack, injecting streams of flaming gas under high pres-. sure and live steam into the smoke in the direction of flow of the latter, leading the smoke from the stack, subjecting it to a water spray, leading It is also obvious that fans cannot force gases itinto a closed container and precipitating the solid constituents therein and then leading the gases into another container and drawing off the gases from different levels in said container.

-3. Apparatus of the character described comprising a Smokestack having no outletto the air,- pipes leading from said stack, exhaust pipes of explosion units discharging into said smoke stack and other pipes discharging live steam into said smoke stack, all of said discharges being directed toward and thus tending to force the smoke into said pipes leading from said stack, a settling tank adapted to receive the smoke from-the smoke stack and'to retain the solid constituents of said smoke, in combination with a tank connected to said settling tank having openings at different levels from which the gaseous contents-of the tank can be drawn off.

EDWARD 

